Telephone apparatus



(No baeu 2 Sheets-Sheet 1-.

' U. H. BALSLEY.

TELEPHONE APPARATUS.

No. 394,951. Patented Dec. 25, 1888.

(No Model.) 1 2 Sheets-Sheet 2.

' U. H. BALSLEY.

V TELEPHONE APPARATUS. N0. 394,951.- Patented Dec. 25, 1888.

Nv PETERS, PMlo-Liihngnphur, Wnhinghn, D. C.

UNTTED STATES PATENT QEETcE.

UPTON II. BALSLEY, OF PHILADELPHIA, PENNSYLVANIA.

TELEPHONE APPARATUS.

SPECIFICATION forming part of Letters Patent No. 394,951, dated December 25, 1888.

Application filed August 2, 1888. $erial No. 281,712. (No model.)

To (all 10. 40710 it may concern.-

Be it known that I, UPTON l-I. BALSLEY, of the city and county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Telephonic Apparatus, of which the following is a specification.

My invention has reference to telephone-- circuits adapted to central-station purposes; and it consists in certain improvements, all of which are fully set forth in the following specification, and shown in the accompanying drawings, which form part thereof.

The object of my invention is to simplify the general construction and arrangement of circuits adapted to central-station work in telephony, and more particularly to greatly increase the efficiency of the apparatus over those now in use, whereby far less space is required and the capacity of the operator to handle the switches is very largely improved.

The great advantages of my improvements may not be very apparent in small centralstation work; but where the number of subscribers is from five hundred to ten thousand, then the decided advantages will be clearly apparent.

My invention, therefore, is especially adapted to large central-station work.

In carrying out my improvements I can dispense entirely with the drops found so necessary in many other systems, and by so dispensing with them the available space or area adapted to switch-board purposes is largely increased, making it possible to place within operative reach of an operator many more subscribers than was heretofore found possible, and at the same time trunk-lines and other objectionable features now in use are dispensed with; but it is manifest that my invention may also be used in connection with drops whenever it is found expedient to employ them, as in the case of distant subscribers. The general plan of the circuits for calling for connections or those at the subscriber's office is substantially the same as now in use in work employing what is known as the Law system. M y switchboard is in a few particulars somewhat similar to those now iii-use; but in operation it differs very materially.

By my improvements I am enabled at but trifling expense to convert the majority of the large central stations in workable apparatus with a greatly-increased list of subscribers and with less space necessary and less labor on the part of the employs in the central station.

any of the central'station plants now in use in our large cities are working at their maximum capacity and under great difficulties. By my improvements I greatly increase the capacity without requiring more space and greatly reduce the operators labor.

In the drawings, Figure 1 is a diagrammatic view illustrating the construction and arrangement of parts and circuits constituting my improvements as applied to complete metallic circuits for the subscribers. Fig. 2 is a similar view of same as used upon singlewire circuits between subscribers and employing the ground as the return; and Fig. 3

is a sectional elevation of one of the switchplugs.

First referring to the closed or metallic circuit system, as shown in Fig. l, we have at the lower part of the figure the central-station apparatus, and at the upper part the subscribers apparatus, and which may be substantially the same as now in use. The central station is provided wit-h the switch-board A, having the plug-tubes B arranged close together and formed of metal. Immediately in the rear of each of these tubes B is a spring-switch, C, normally resting against a contact, D. \Vhen a plug, H, such as shown in Fig. 3, is inserted into the tube B, the metallic head J presses the switch 0 to one side and breaks contact with D, and simultaneously the outer metal cylinder, 71 of the plug makes contact with the tube B, thus breaking one contact and making another. The head J and its extension are supported in a fixed relation to the cylinder 7L of the plug H by the insulating medium I. These plugs maybe of any other suitable construction, 5

they at best being simply special forms of switches requiring but little superficial space. As shown, there are three sets of these switches, B C Dthat is to say, there are two other switches, C D, which are connected by circuits E and F with the primary or first switch, connecting with the line P leading to the subscriber, and connection may be made with said subscriber by inserting a plug in either of these latter switches (in other switchboards) in place of the first. The object of this is that each operator can attend to a given number of subscribers, and while having control of the wires of particular subscribers he can connect them with any of the other subseril'lers. Thus an operator at switch-board No. 1 can connect his subscribers with each other or with any of the other subscribers whose lines would terminate in the switch-imard of the duplicate or triplicate switches shown, and one set of such switches would be within reach of operator at No. 1. An iwierator at No. 2 switch-boanl would in like manner be able to connect his subsm'il'lers with each other or with subscribers from No. 1 or No. switcli-boards. This gives each operator full range of all subscribers. All the subscribers on the call-circuit of any operator are considered as his subscribers, and would be said to be the subscribers of his switchboard. If the operator at No. 1 switch-board inserts a plug in the first switch, it is apparent that contact at I) is severed and that every switch in the entire central station at the other switch-boards corresponding to this subscriber is cut out and he cannot be interrupted by duplicate connection. After connection of all of the switches C i) of all of the switch-boards corresponding to one operator, the contacts 1) thereof are connected by wires (l together and connect with the call-line T, having the operatofs telephone U, and extending out into the city and connecting with the sul scribers of the operator to whom the receiver U corresponds.

As shown in Fig. l, the telephone l7 belon to the subscriber at switch-board No. 1, and line T would connect with the subscrilwi' on circuits 1, P, and IP". Lines 1 I 1 are line-wires leading to diiii'erent subscribers, the apparatus of one of which subscrilun's alone being shown. The number of subscribers on such a wire in the construction shown in Fig. 2 would be inverse proper-- tionally to the duty required of it. The return-wire "m from the subscriber connects the tube B of the switch (1 l) connecting wit h the line P leading to this subscriber, and all of the correspomjling tubes, 13, of the respective switch-boards Nos. 2 and 3 are connected, as shown, by wires 0. In like manner the other tubes are connected by wires 0 and so thata contact at one switch-board will connect with all correspondingtubes at the other switch-boards.

Connection is made by the operator by means of two plugs, 11 ll, having their heads .l J connected by a flexible circuit, K, and their tubular parts it connected by flexible circuits K to switches 711k, adapted to contact with an alarm or call circuit, L, containing a battery, Z, or other source of electric power, the other end of which is grounded. The

switches 7: ll: when released close a circuit, is, byback-stops, so as to couple the tubular parts lb 72. of the plugs. The operator at any switchboard would have suiiicient of the plugsll as to make all connections which could be called. for. For simplicity, lhavc shown but one set of said switch-plugs.

The operation will nowbe understood. The subscriber lifts his receiver-N oil the level-M, shifts the switch Q, and calls for connection with, say, the subscriber of wire I. The ind uced current would pass from ind uction-coil of the local battery of the calling subscriber by R Q. q I (l I) E (l i) l (1 .l) G 'l, operatoFs-recciver l T [g Q R N, to induction-coil oi local battery again. ,llaving made his wants known, the subscriber waits for the signal that the connection is made. Tlheoperator places the switch-plugs ll it into the holes or tubes 1;, corresl londing to lines l and l, and this breaks switch 1) ol. each of said circuits and connects 13 l; of said circuits by tubular parts 71, wires K, and circuit /t of switches It. It also connects the switches (I (1 of P and P through heads .l of the plugs and wires K. \Vhen this is done, the ()I'JOlLtOl' temporarily presses strongly thelever 70 to call up that subscriber on line i, and presses for an instant upon switch lgcorrcspondi n g to the subscriber on line I", to indicate that the connection is made, the signal given to the calling subscriber bein g a tap. Current on signali ng the sul'iscribcr being called up passes by groundbattery [L 7: K 71 of ll 13, line In, bell-magnets wire III, through switch-contacts M. M to ground. The two subscribers are now coiu lled, and the switch (,1 is shifted. The induced current from local battery and induction-coil )asses,by wire li,switch r, switch Q, line I, to t, plug-lwad .l', wire K to othcu' plug-hcznl, .l, to and to line l to other subscriber, returning by wire m of l subscriber to to tube It, thence by plugs, cylinders 71, and wire h to tube 1 of subscriber on 1 line shown, and by m, bell 0, contact M to r, through switch Q to R, to receiver N, and to induction-coil of transmitter. When the subscribers are not; using the instruments, the receiver is hung upon the switcl'l-lever M, and is drawn down, making contact with ground by switch M, and as the lever M is connected with the arn'lature of the hell by wire m and wire cir cuit m is broken at M lli the operator, in call big up, would send the current by wire on, magnets 0, through back contact: of the armature of bell, by wire In to lever M and by switch M. to ground. In. this case the bell is a vibrator, ringing rz'q iidly. \Yhen the subscriber is calling up and has the receiver l\' down, then m is out olf circuit, and the eleetric bell. is converted into a stroke-bell, requiring the operator to interrupt; the circuit to make it strike. ly this means a distinct ive signal may be given to the calling subscriber it the subscribeifs line he calls for is busy. In this latter case the current passes through m 0, commits M? M to contact r, and by wire S to ground. One of the particular features which makes this invention so advantageous is that the receiver of the operator of any switch-board is in circuit with every switch of his subscribers, whether they be on his board or on the boards of all other operators, and such switches are not in circuit with the receivers of any other operator, and, further, that when any other operator has cut out one of the subscribers first mentioned by connection then the receiver of the tirst-mentioned operator is cut out of circuit with said subscriber.

Referring now to Fig. 2, which shows the arrangement of my improvement as applied to a metallic outgoing circuit with a ground return. In this arrangement there is no metallic circuit m. The arrangement at the cen tral station is in all material respects the same as in the ease of the metallic-circuit system shown in Fig. 11. The signal-circuit T in this case is preferably looped, as shown, forming two paths for the current from the subscribers, and thus making the system doubly sure in its operation. The apparatus at the subscribers office is shown in the upper part of Fig. 2, and the connections are made as follows: The linewire P connects with the bell-magnets O, and through the back-stop connects by the wire m with the receiver-lever M, and this receiverlever through the contact H connects with the ground, or when the receiver is removed For use it is connected with the receiver-circuit R, which, after passing through the induction-coil ot the transmitter 21, passes to the switch Q, and by S to ground; It will thus be seen that it the operator at the central station wishes to signal the subscriber he simply inserts the plug II (in this case one metallic piece) into the proper tube B and presses the contact-switch L. This sends the current from the battery through K head .I contact (1, line I, signal 0, circuit m contact M, to ground. Upon inserting another plug, H, as shown, the said subscriber so signaled may be coupled with the subscriber on P circuit, and

4 both subscribers will then be coupled through central station by wire K circuit 1;, of backstops oit' levers A, and their other connection will be through the ground.

\Vhen the subscriber wishes to signal the central station t'or connection, he presses the switch Q, so as to connect the circuit R with branch wire '.l,c(mnecting with the main central-stat ion circuit, and simultaneously therewith he removes the receiver, which closes the circuit from the line Pthrough O m, switch lever M, to It. This will connect the subscriber in complete metallic circuit with the central-station operator, and at the same time out out the ground-circuit t'ormerly made by switch M. The operator is then informed through the metallic circuit with whom the subscriber desires to be coupled.

It is evident that the circuits at the subscribers office in Fig. 2 may be arranged substantially similar to those shown in Fig. 1, as

the particular arrangement of the subscribers local apparatus is of secondary importance.

The employment of a double call-circuit, T, is very important, as it gives to the operator two ways of signaling up the central operator, and it is inexpensive, as it may extend in all directions and return to central station, having subscribers throughout its entire length.

The circuits 0 O O 'in Fig. 2 are simply test-circuits to enable an operator at Nos. 2 or 3 switch-board to ascertain if any subscriber at No. 1 switch-board is talking. In the case of Fig. 1 these circuits perform the double duty of test-circuits and line-circuits by connection with circuits m.

It is evident that the minor details of my invention maybe modified in numerous ways, well known to electrical engineers, without in the least departing from the spirit of my invention.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In central-station apparatus for telephony, the combination of two or more switchboards corresponding to different operators, switches in each of said switeh-lmards, corresponding in number to all of the subscribers.

of the central station and normally in electric connection with the subscribers lines, normally coni'iecting circuits between all of the switches of all of the switch-boards which correspol'ld to the same subscriber, a call-circuit for each switch-board connecting with its subscribers and electrically connected with the connecting-circuits of said subscribers switches, a receiver in each of said call-circuits close to the switch-board, a signal-bat.- tery or source of electric power, switch-plugs or cq ui valcnt devices for connecting different subscribers, and switches for connecting the battery or source of electric power with the subscribers circuits.

2. In central-station apparatus for telephony, the combination-0t two or more switchboards corresponding to different operators, switches in each of said switch-boards, corresponding in number to all of the subscribers of the central station and normally in electric connection with the subscribers lines, normally connecting circuits between all of the switches of all of the switch-boards which correspond to the same subscriber, a call-circuit for each switch-board connecting wit-h its subscribers and electrically connected with the eonneeting-circuits of said subscribers switches, a receiver in each of said call-circuits close to the switch-board tubes or contact parts in line with each of the switches of the subscribers, connecting-circuits between the subscribers and each of the tubes or con tact parts of all of the switch-boards corresponding-to each of said subscribers, a signalbattery or source of electric power, switchplugs or equivalent devices for connecting diil'erentsubscribers through the contacts and switches of the switich-ljioards, and switches or connecting the battery or source of elecnecting with said circuits, an operat'ols re-;

ceiver in said call-circuit, a series ot' subscribers circuits connecting with the switches of the switch-board, to which the operators receiver corresponds, and circuit con necting and breaking switch-plugs or equivalent devices to connect two subscribers and interrupt the circuits in the switch-iniards ol' the subscribers so coupled beyond the point ot coupling up.

4. In a tele 'ihonic station, the combination of a series of sivitclelmards, each having a number of subscribers controlling separate operators, switches l) for each subscriber and connected with the line-wires, connecting-circuits E la connectingcach ot the corresponding switclms ot' each switch-board in series, a call-circuit, '1, connected with the circuits E, h, and G, correspomling to the subseribers ot one switch-board, an operators receiver in said call-circuit, and suitable devices for breaking au ot' the switches (11) and simultaneously coupling the corresponding subscribers circuits connecting with the parts of said switches.

5. In a telephonic central station, the combination of a series of switchdjioards, each having a number of subscribers contlolli'ng separate operatm's, switches l) for each subscriber and connected with the line-wires, connecting-circuits E i (t, connecting each of the correspomliug switches of each switchboard in series, a call-circnit,l",norn'iallyconnectcd with the t'lltilillh E, I and (4r, correspending to the subscribers of one switchtmard, an operators receiver in said call-circnit, contacts 13, arranged in front of the switches (J l), line-circuits m, leading from the various subscribers and connecting with the corresponding contacts ii, of all the switchboards, and plugs ll ll, having heads to simultaneously break t he circuits at (J l), to connect two subscribers circuits terminating in parts (I and to connect two subscribers circuits at, terminating in two contacts B.

of switch-boards each having switches connecting with all of the subseriliiers of the station, connecting-circuits between all of the switches eorrespomling to each subsca-iber, a cz'ill-circuit from the OpPlttl'Ol' oit' each switchboard at the central station to the subscril'iers of said switell-board, a receiver in said callcircuit, and circuit-breakersunderthe control of the operator of each switch-board to cut out any subscriber of another switch-board t'rom connection beyond said operator and. also to cut out the attending operator of the subscriber.

7. In a telephonic centra l-station system,

- the combimttion ot a series (it subscribers, two

ti. in a telephonic central station, a series 1 switch boards having switches corrcspomling in number to all ot' the subscribers connecting-circuits, and circuitcoup1ing devices for connecting two subscribers in circuit, a callcircnit for each ot' said switch-boards, each including a portion of the subscribers and both including all of the subscribers, and each ,-oni1eeting with allot the switches of their respective switch-boamls, and a telephonic receiver in each of said call-circuits close to the switch-boards tor the operatofs use.

b. The combination of a series of subscribers, a looped nu tallic call-circuit 'lcadil'ig from a central station and in connection with the various sul )scril'ie rs, l inc-circuits leadiii g from the central station to the subscribers, an operators receiver t'or said subscribers line-circuits, connecting-circuits including the receiver between the looped call-circuit and each of the line-circuits of the subscribers, a signal or alarm tor each of the subscribers normally in circuit with the looped call-circuit, and switches at the central station for coupling into operative circuittwo subscribers limia-circnits 'independently of the looped call-circuit.

.I. A looped metallic call-circuit, two subscribers speech transmitting instruments connected with the looped Ctlll'Cll'CllllT, a central station, an operators receiver in circuit with the lotimed caIll-circuit, and connectingcircuitsbetween the s1icech-t;r:msmitting instruments ol the two subscribers independent of the looped call-circuit, whereby they may be coupled :tor couversatitm and the looped. call-circuit used for signaling only.

In testimony of which invention 1 hereunto set my hand.

lTlTON Il'. ILXIJSIJEY. Witnesses:

E. M. l'iREGKYI'NREICL), lCaNEs'r ilowaao I I lN'lEl-L 

